When it was determined that Chris Benoit killed his wife, their son, and himself in a three-day period in June 2007, the world had many questions. People both inside and outside of the pro-wrestling industry couldn’t make sense of what caused Benoit’s actions and wondered what was going on in his mind at the time. While there has been speculation that the motive was a combination of steroid use and marital problems, another popular theory is that it was because Benoit was suffering brain damage as a result of concussions.

In an attempt to find answers, Benoit’s brain tissue was investigated by the Sports Legacy Institute (known today as the Concussion Legacy Foundation), an organization that researches the long-term effects of concussions. While the world will never know the exact events that took place leading up to the murder-suicide or why the tragic act was committed, much has been learned about what state Benoit’s brain was in.

Chris Benoit had extensive brain damage

In September 2007, Julian Bailes, the chairman of neurosurgery at West Virginia University and a founding member of the Sports Legacy Institute, announced the findings of his organization, stating that Chris Benoit’s brain had undergone many changes from concussions. "These extreme changes throughout Chris Benoit’s brain are enough to explain aberrant behavior, including suicide and even homicide," Bailes said (via ESPN).

However, Bailes added that he felt their findings were not evidence that brain damage was the reason for the murder-suicide. "I think even if you had a great psychiatric input on this case that you couldn’t come up with why human behavior can become so severe," Bailes said (via ABC News).

The Sports Legacy Institute’s post-mortem diagnosis was that Chris Benoit was suffering from a form of brain damage named Chronic Traumatic Encephalopathy (CTE). Dr. Robert Cantu compared the condition of Benoit’s brain to a man aged 80 or older with "very severe" Alzheimer’s disease, adding, "His was the most extensively damaged of the brains we have examined so far." According to ESPN, Benoit’s brain was "liquefied" by the time police officers found his body, which was only one day after he died.

In addition, Science Daily reported that abnormal proteins in Chris Benoit’s brain "has been confirmed to cause neurodegeneration, cognitive impairment and dementia."